cmd/api: compare multiple contexts

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5626045

diff --git a/src/cmd/api/goapi.go b/src/cmd/api/goapi.go
index c8fc9cfae7f4caf3b4f3b8e12c29f01d634e91e4..ef1b8c5d938d2676f13c59307e3a054896187095 100644 (file)
--- a/src/cmd/api/goapi.go
+++ b/src/cmd/api/goapi.go
@@ -34,6 +34,27 @@ var (
        verbose   = flag.Bool("v", false, "Verbose debugging")
 )
 
+var contexts = []*build.Context{
+       {GOOS: "linux", GOARCH: "386", CgoEnabled: true},
+       {GOOS: "linux", GOARCH: "386"},
+       {GOOS: "linux", GOARCH: "amd64", CgoEnabled: true},
+       {GOOS: "linux", GOARCH: "amd64"},
+       {GOOS: "darwin", GOARCH: "386", CgoEnabled: true},
+       {GOOS: "darwin", GOARCH: "386"},
+       {GOOS: "darwin", GOARCH: "amd64", CgoEnabled: true},
+       {GOOS: "darwin", GOARCH: "amd64"},
+       {GOOS: "windows", GOARCH: "amd64"},
+       {GOOS: "windows", GOARCH: "386"},
+}
+
+func contextName(c *build.Context) string {
+       s := c.GOOS + "-" + c.GOARCH
+       if c.CgoEnabled {
+               return s + "-cgo"
+       }
+       return s
+}
+
 func main() {
        flag.Parse()
 
@@ -48,28 +69,54 @@ func main() {
                pkgs = strings.Fields(string(stds))
        }
 
-       w := NewWalker()
        tree, _, err := build.FindTree("os") // some known package
        if err != nil {
                log.Fatalf("failed to find tree: %v", err)
        }
-       w.tree = tree
 
-       for _, pkg := range pkgs {
-               w.wantedPkg[pkg] = true
+       var featureCtx = make(map[string]map[string]bool) // feature -> context name -> true
+       for _, context := range contexts {
+               w := NewWalker()
+               w.context = context
+               w.tree = tree
+
+               for _, pkg := range pkgs {
+                       w.wantedPkg[pkg] = true
+               }
+
+               for _, pkg := range pkgs {
+                       if strings.HasPrefix(pkg, "cmd/") ||
+                               strings.HasPrefix(pkg, "exp/") ||
+                               strings.HasPrefix(pkg, "old/") {
+                               continue
+                       }
+                       if !tree.HasSrc(pkg) {
+                               log.Fatalf("no source in tree for package %q", pkg)
+                       }
+                       w.WalkPackage(pkg)
+               }
+               ctxName := contextName(context)
+               for _, f := range w.Features() {
+                       if featureCtx[f] == nil {
+                               featureCtx[f] = make(map[string]bool)
+                       }
+                       featureCtx[f][ctxName] = true
+               }
        }
 
-       for _, pkg := range pkgs {
-               if strings.HasPrefix(pkg, "cmd/") ||
-                       strings.HasPrefix(pkg, "exp/") ||
-                       strings.HasPrefix(pkg, "old/") {
+       var features []string
+       for f, cmap := range featureCtx {
+               if len(cmap) == len(contexts) {
+                       features = append(features, f)
                        continue
                }
-               if !tree.HasSrc(pkg) {
-                       log.Fatalf("no source in tree for package %q", pkg)
+               comma := strings.Index(f, ",")
+               for cname := range cmap {
+                       f2 := fmt.Sprintf("%s (%s)%s", f[:comma], cname, f[comma:])
+                       features = append(features, f2)
                }
-               w.WalkPackage(pkg)
        }
+       sort.Strings(features)
 
        bw := bufio.NewWriter(os.Stdout)
        defer bw.Flush()
@@ -81,7 +128,7 @@ func main() {
                }
                v1 := strings.Split(string(bs), "\n")
                sort.Strings(v1)
-               v2 := w.Features()
+               v2 := features
                take := func(sl *[]string) string {
                        s := (*sl)[0]
                        *sl = (*sl)[1:]
@@ -99,7 +146,7 @@ func main() {
                        }
                }
        } else {
-               for _, f := range w.Features() {
+               for _, f := range features {
                        fmt.Fprintf(bw, "%s\n", f)
                }
        }
@@ -112,6 +159,7 @@ type pkgSymbol struct {
 }
 
 type Walker struct {
+       context         *build.Context
        tree            *build.Tree
        fset            *token.FileSet
        scope           []string
@@ -221,8 +269,17 @@ func (w *Walker) WalkPackage(name string) {
        }()
        dir := filepath.Join(w.tree.SrcDir(), filepath.FromSlash(name))
 
-       info, err := build.ScanDir(dir)
+       var info *build.DirInfo
+       var err error
+       if ctx := w.context; ctx != nil {
+               info, err = ctx.ScanDir(dir)
+       } else {
+               info, err = build.ScanDir(dir)
+       }
        if err != nil {
+               if strings.Contains(err.Error(), "no Go source files") {
+                       return
+               }
                log.Fatalf("pkg %q, dir %q: ScanDir: %v", name, dir, err)
        }